Ruling pencil



March 3, 1953 D. G. FALcoNER RULING PENCIL Filed Jan. 14, 1952 INVENTOR.

D- G. FALCONER ATTORNEY Patented Mar. 3, 1953 RULING PENCIL David Gray Falconer, Berkeley, Calif. Application January 14, 1952, Serial No, 266,424

14 claims. (c1. ca -41) This invention relates to geometrical devices,

more particularly drafting equipment and speciiically to a ruling pencil of the characteremployed in making precise and accurate drawings where it is necessary to have lines of substantially uniform widths and appreciably smaller than the diameter of the lead.

The invention relates to a ruling pencil hav- `ing the features abovementioned and in addition aV pencil capable of utilizing lead which can be adjusted easily and readily removed andreplaced. l

In the making of drawings it has been an annoying as well as a time consuming problem for the draftsman to maintain his pencil in a suiciently sharpened condition to produce a .thin uniform line. This has been particularly true where a relatively soft pencil has been used since rapid wear of the lead has resulted in a line gradually increasing in width until the same became unduly wide and detracted both from the-accuracy and from the appearance of the drawing.

When wood pencils are utilized by a draftsman it is necessary Ato sharpen the same by removing a portion ofthe wood with a knife and thereafter to sharpen the lead by use of a le or sandpaper pad. These are time consuming operations which must be continued as long as the pencil is in use. Also the pencil cannot be used for its full length because when it becomes short it cannot be conveniently grasped in the hand.

f Mechanical pencils have been produced for use 1 by draftsmen, which pencils have a shank or handle which is hollow. to receive lead and a chuck to hold'such leadfb'utl the majority of these have required a lead of substantially the same diameter as that found', in `conventional '-,woodpencils and it is necessary tosharpen these pencils by means of a le or sandpaper pad. In

such cases a considerable portion lof the lead must project from the chuck in order to provide proper contact between the lead and a straight edge or other instrument utilized in making the 2 a pencil for use by draftsmen of simple and inexpensive construction, susceptible of high quantity production and which can be produced of readily available materials by relatively unskilled labor.

Another objectof the invention is -toprovide a pencil of the character described employing a lead without the same having to be sharpened and which provides a penciled line of uniform width vregardless of the wear of the lead as well as a pencil of a construction such that the lead is both adjustable and replaceable. l

A further object of the invention is to provide a pencil for use by' draftsmen in which pencil the structure is such that inadvertant displacement of the lead inwardly or outwardly of the pencil is prevented and there is an elongated shank and a finger gripping portion with means to move or project the lead outwardly of the grippingr portion as the lead is consumed.

Further objects and advantages of the invenv tion will be apparent from the'following description taken in conjunction with the accompanying drawings, wherein:

Fig. l is a perspective of a draftsmans pencil in accordance with this invention;

Fig. 2, a vertical section of the internal construction of the pencil of Fig. l;

Fig. 3, a view similar but at right angles to that of Fig. 2;

Fig. 4, a fragmentary perspective of the pencil in full lines in vertical operating position and-in phantom lines in two' angular positions;

Fig; 5, a fragmentary elevation illustrating the relationship of the pencil lead andjpaperand the manner in which the-lead wears during -use-yand Fig. 6, an elevation at right angles to that of Fig. 5 and illustratingthe contour of the lead in contact with the paper.

line of increasing width as the lead wears and consequently any device which provides a pencil line of uniform width regardless of the wear of the lead represents a contribution to the art.

An object of the invention is the provision of 5` shank lil.

With continued reference to the drawing a pencil in accordance with the present invention has an elongated shank I0 terminating at one end in an enlarged shoulder portion II, the external surface `of which is provided with screw threads I2. The purpose of these screw threads will presently appear. The opposite end of the shank I U may be provided with a bore I3 for the reception of spare leads I4 and the bore I3 may be conveniently closed by a cap I5 provided with screw threads I6 for retaining the same in The external surface of the cap I5 may have a knurled portion I1 to provide a rm finger grip `or if desired the cap I5 may be retained in thebore I3 by a sliding friction t.

A nger engaging piece I8 is provided with a bore having screw threads I9 designed to mate with the screw threads I2 on enlarged portion I I of shank I and rotation of finger piece I8 with relation to shank lu will move the same inwardly or outwardly thereof. In order to provide a firm engagement between threads I2 and I9 the finger engaging piece I8 may be provided with vertical slots which results in a firm frictional engagement between the threads and prevents inadvertant relative rotation.

Finger engaging piece I8 is provided adjacent the lower end thereof with a transversely disposed yoke having spaced arms 2| and 22 provided with aligned bores for slidably and rotatably receiving a relatively thinA lead 23. Dis,-

posed between the arms 2|. and 22 and friction-- ally engaging and receiving the lead 23 is a friction drive member 24 having an enlarged collar 25 adjacent the lower end thereof, and an elongated portion 23 extending upwardly therefrom. Disposed between the. upper end. of the portion 26 and the lower surface of. arm' 22. of. the yoke are spacing washers" 2.1. which take.y up. excessive play or clearance and serve to prevent inadvertant axial movement of the friction drive member 24 and the lead; 23. Drive member 24 may be formed of rubber; neoprene or other suitable resilient material. and this member serves to il'rxnly grip the lead` 23 and: upon rotation 0f the member" 24 lead' 23 will rotate*` therewith and in view ot the frictional engagement bethe'l member 24 and lead 23: the latter may be moved axially throughv the member 24- as the lead 23 wears away.

Means is provided for projecting the lead 23 through the friction dri-ving member 24 to compensate for wear and this means may' convenientl-y` take the form` of a plunger 28 secured in an aperture 29 inl the lowerl end of shank I3" in any desiredV manner such: as by soldering or welding or if desired plunger 23A may constltute a drive fit in the aperture29. A bore 30 may be provided in the nnger engaging piece I6 whichl bore is concentric with the aligned bores in the yokel arms 2| and- 22 and the diameter oi' board' 30 is'such as to snugly but slidably receive the plunger 23'.A

It will be seenl therefore that upon the rotation of the shank I0 with relation. to the finger piece Il? to` move the shank I0 downwardly into the finger piece I8' that the plunger 28 will engage the upper end' of lead 23 and `project the same through thefrictionV driving. member 24 to compensate for weer of' ther lead 23. Uponv the plunger 28V reaching" the extremev downward. position at which time. the lead 23r has beerr fully extended.' the. remaining portion of the. lead within the friction driving member' 2'4 may be removed' andA a new lead inserted. at. which time the plunger 28 will be'- retracted by relative rotation between the shank I'U and the finger engaging piece. I 8f to accommodate-the newlead..

Thek pencil of4 this invention is designed to be" used in either theright orA left hand. and if itis desiredto draw a line having a width equal to the diameter of the lead 23 the pencil will. be held in a. vertical. position as. shown in fullI lines in Fig. 4. with the collar 25 of the friction driving member 24:l in engagement with one edgey of a straight edge 3|. Movement of the pencilinthe. direction of the. solid line arrow 32 or the dotted line arrow 33 will result in drawing aline having a width equal to the diameter of the lead 23 and the lead 23 will be` rotated by reason of the frictional engagement between the collar 25 and the straight edge 3| resulting in a line 34 of uniform density. When a pencil is being used in the right hand and it is desired to draw a line 34 of relatively narrow width the pencil is inclined as shown in phantom at 35 in Fig. 4 and moved in the direction of the solid line arrow 32. Conversely when the pencil is used in the left hand it is inclined to. the position shown in phantom lines 36 in Fig. 4V and' moved in the direction of the dotted line arrow 33.

As shown in Figs. 5 and 6 with the pencil in either inclined position and with the collar 25 engaging the straight edge 3| the lead 23 will engage the paper 31 and as the pencil is moved ineither directionor as shown in Fig. 5 toward the right, the lead will be rotated by engagement of the collar 25 with the straight edge 3| and the lead will wear'in the form of a cone 38. The arcuate surface 39 ofthe cone. is in engagement with the paper 31' as shownin Fig. 6 and consequently it will be seen that. the width ofthe line formedv by the pencil will be determined by thev radius of the. arcuate. surface 39. This will be substantially a line contact and consequently the line 34 will be relatively narrow and in. view of the. fact that the pencil. lead' 23 is continuously rotated during the ruling process the arcuate surface 3S will be maintained and a fiat will not form onv the lead 23' which would result in a gradual increase in width of the line 34. Consequently a line of uniform width will be obtained and this will be a relatively nne line of considerably less width. than the diameter of the lead 23. Identically the same action will occur. if the pencil is. inclined. in the opposite direction and moved toward ther left as. viewedV in Fig. 5.

It will. be seen that by the above described invention there has been provided a relatively simple pencil for use by draf-temen in which means is provided for maintaining a line of uniform width and which line is of considerably less width than the diameter of the lead utilized in the pencil. Furthermore means is provided for conveniently adjusting the lead to compensate the wear and such lead may be easily renewed when necessary. The pencil` may be formed of metal, plastics or any other suitable material.

It will be obvious to those skilled in the art thatv various changes may be made in the invention. without departing from the spirit and scope thereof and therefore the .invention is not limited by that which. is; shown in the drawings and described in the specification but only as indicated. in. the appended claims.

What, is claimed l. A ruling pencil` comprisingl an elongated shank having a threaded enlargement on one end thereof, a bore in its opposite end for receiving spare. leads, and a` cap for closing said bore, a plunger extending axially and4 concentrically from said enlargement, a finger engaging piece having a threaded bore in one end thereof and threadedly engaging. said enlargement, said 4piece being partially split. longitudinally to provide4 a relatively tight frictional engagement between said threads tol prevent inadvertant relative rotation. between said shank and said. piece, a reduced. bore in said piece for receiving said plunger, a yoke on the opposite end of said piece having transversely disposed spaced arms, aligned bores in said arms communicating with said reduced bore,r a. lead slidably and rotatably received in said aligned bores and extending into said reduced bore, a resilient rotating member received on said lead and frictionally gripping the same between said arms, an enlarged collar on said rotating member for engaging a straight edge and spacing washers between one endof said rotating member and one of said arms to prevent excessive end play whereby upon movement of said pencil along a straight edge with said collar engaging the same said lead will be rotated to provide a line of uniform width and upon relative rotation between said shank and said piece said plunger will engage said lead to project the same through said rotating member to compensate for wear of said lead.

2. A pencil comprising an elongated shank having av threaded enlargement on one end thereof, a plunger extending axially from said enlargement and concentric therewith, a finger engaging piece having a threaded bore in one end thereof and threadedly engaging said enlargement, said piece being partially split longitudinally to provide a relatively tight frictional engagement between said threads to prevent inadvertant relative rotation between said shank and said piece, a reduced bore in said piece for receiving said plunger, Ia yoke on the opposite end of said piece having transversely disposed spaced arms, aligned ybores in said arms communicating with said reduced bore, a lead slidably and rotatably received in said aligned bores and extending into said reduced bore, a resilient rotating member received on said lead and frictionally gripping the same between sai-d arms, an enlarged collar on said rotating member for engaging a straight edge and spacing washersV between one end of said rotating member and one of said arms to prevent excessive end play whereby upon movement of said pencil along a straight edge with said collar engaging the` same said lead will be rotated to provide a line of uniform width and upon relative rotation between said shank and said piece said plunger will engage said lead to project the same through said rotating member to compensate for wear of said lead.

3. A pencil comprising an elongated shank having a threaded enlargement on one end thereof, a plunger extending axially from said enlargement and concentric therewith, a finger engaging piece having a threaded bore in one end thereof and threadedly engaging said enlargement, said piece being partially split longitudinally to provide a relatively tight frictional engagement with said threads to prevent inadvertantV relative rotation between said shank Vand said piece, a reduced bore in said piece for .receiving said plunger, a yoke on the opposite end of said pieoe having transversely disposed spaced arms, aligned bores in said arms communicating with said reduced bore, a lead slidably and rotatably received in said aligned bores and extending into said reduced bore, a resilient rotating member received on said lead and frictionally gripping the same between said arms and an enlarged collaron said rotatingr member for engaging a straight edge whereby upon movement of said pencil along a straight edge with said collar engaging the same, said lead will be rotated to provide a line of uniform width and upon relativ-e rotation between said shank and said piece said plunger will engage said lead to project the same through said rotating member to compensate for wear of said lead.

4. A pencil comprising an elongated shank having a threaded enlargement on one end thereof, a plunger extending axially from said enlargement and concentric therewith, a iinger engaging piece having a threaded bore in one end thereof and threadedly engaging said enlargement, a reduced bore in said piece for receiving said plunger, a yoke on the opposite end of said piece having tranversely disposed spaced arms, aligned bores in said arms communicating with said reduced bore, a lead slidably and rotatably received in said aligned bores and extending into said reduced bore, a resilient rotating member received on s-aid lead and frictionally gripping the same between said arms, and an enlarged collar on said rotating member for engaging a straight edge whereby upon movement of said pencil along a straight edge with said collar engaging the same, said lead will be rotated to provide a line of uniformwidth yand upon relative rotation Vbetween said shank and said piece said plunger will engage said lead to project the same through said rotating member to compensate for wear of said lead.

5. A pencil comprising an elongated-v shank having a threaded enlargement on one end thereof, `a plunger extending axially from said enlargement and concentric therewith, a nger engaging piece having a threaded bore in one end thereof and threadedly engagingsaid enlargement, a reduced bore in said piece for receiving said plunger, 4a yoke on the opposite end of said piece having transversely disposed spaced arms, aligned bores in said arms communicating with said reduced bore, a lead slidably and rotatably received in said aligned bore and extending into said reduced bore and a reslient rotating member received on said lead and frictionally gripping 'the sam-e between said arms whereby upon movement of said pencil along a straight edge with said rotating member engaging the same said lead will be rotated to provide a line of uniform width and upon relative rotation between said shank and said piece said plunger will engage said lead to project the same through said rota-ting member to compensate for wear of said lead.

6. A pencil comprising an elongated shank having a threaded enlargement on one end thereof, a plunger extending axially from said enlargement and concentric therewith, a nger engaging piece having 'a threaded bore in one end thereof and threadedlv engaging said enlargement. a reduced bore in said piece for receiving said plunger, a recess in the opposite end of said piece providing spaced arms, aligned bores in said arms communicating with said reducedlbore, a lead slidably and rotatably received in said aligned bores and extending into said reduced bore and a resilient rotating member received on said lead and frictionally gripping the same between said arms whereby upon movement of said pencil along a straight edge with said rotating member engaging the same said lead will be rotated to provide a line of uniform width and upon relative rotation between said shank and said piece said plunger willengage said lead to project the same through said rotating member to compensate for wear of said lead.

7. A pencil comprising an elongated shank having screw threads on one end thereof, a plunger extending axially from said shank and concentric therewith, a finger engaging piece having a threaded bore in one end thereof and threadedly engaging said shank, a reduced bore in said piece for receiving said plunger. a. re-

aeaaeaa tees: in the opposite end of said piece providing spaced arms. aligned bores in said arms communicating with said reduced bore, a lead slid- Aably and rotatably received in said aligned bores and extending into said reduced bore and a` resilient rotating member received on said lead and frictionally gripping the same between said arms whereby upon movement of said pencil along a straight edge with said rotating .member engaging the saine` said lead will be rotated to provide a line of uniform width and upon relative rotation between said shank and said piece said plunger will engage said lead to project the same through said rotating member to compensate for wear of said lead.

. 8. A pencil comprising an elongated shank 4having screw threads on one end thereof, a finger engaging piece having a threaded bore in one end-thereof and threadedly engaging said shank. a recess in the opposite end of said piece providing spaced arms, aligned bores in said arms communicating with said reduced bore, a lead slidably and rotatably received in said aligned bores and extending into said thread- .ed bore and a resilient rotating member re- .v ceived on said lead and frictionally gripping the same between said arms whereby upon movement of said Pencil along a straight edge with said, rotating member engaging the same said lead will be rotated to provide a line of uniform width and upon relative rotation between s-aid shank and said piece said shank will engage said lead to project the same through said rotating member to compensate for wear of said lead.

9. A pencil comprising an elongated shank having a iinger engaging portion at one end thereof and a bore in. the opposite end for receiving spare leads, a cap for closing said bore, a. reduced axial bore in said nger engaging portion, a yoke on the end of said finger engaging portion having transversely disposed spaced arms, aligned bores in said arms communicating with said reduced bore, a lead slidably and rotatably received in said aligned bores and extending into said reduced bore, a resilient rotating member received on said lead and' frictionally gripping the same between said arms, an enlarged collar on said rotating member for engaging a straight edge provide a line of uniform width.

l0. A. pencil comprising an elongated shank A-having a iinger engaging portion at one end thereof, a reduced axial bore in said finger engaging portion, a yoke on the end of said finger engaging. portion having transverse disposed spaced arms, aligned boresl in said arms communicating, with said reduced bore, a lea-d slidably and rotatably received in said aligned bores and extending into said reduced bore, a resilient rotating member receivedv on said lead and frictionally gripping the same between said arms, an enlarged collar on said rotating member for engaging a straight edge and spacing washers between one end of said rotating member and one of said arms to prevent excessive end play whereby upon movement of said pencil along a straight edge with said collar engaging the same said lead will be rotated to provide a line of uniform width.

11. A pencil comprising an elongated shank having a iinger engaging portion at one end thereof, an axial bore in said nger engaging portion, a yoke on the end of said iinger engaging portion having transversely disposed spaced arms, aligned bores in said arms communicating with said axial bore, a lead slidably and rotatably received in said aligned bores and extending into said axial bore, a resilient rotating member received on said lead and frictionally gripping the same between said arms and an enlarged collar on said rotating member for engaging a straight edge whereby upon movement of said pencil along a straight edge with said collar engaging the same said lead will be rotated to provide a line of uniform width.

12. A pencil comprising an elongated shank having a finger engaging portion at one end thereof, an axial bore in said finge;` engaging portion, a yoke on the end of said linger engaging portion having transversely disposed spaced arms, aligned bores in said arms communicating with said axial bore, a lead slidably and rotatably received in said aligned bores and extending into said axial bore and a resilient rotating member received on said lead and frictionally gripping the same between said arms whereby upon movement of said pencil along a straight edge with said member engaging the same said lead will be rotated to provide a line of uniform width.

13. A pencil comprising an elongated shank having a finger engaging portion at one end thereof, a yoke on the end of said nger engaging portion having transversely disposed space arms, aligned bores in said arms, a lead slidably and rotatably received in said aligned bores and a resilient rotating member received on said lead and frictionally gripping the same between said arms whereby upon movement of said pencil along a straight edge with said member engaging the same said lead will be rotated to provide a line of uniform width.

14. A pencil comprising an elongated shank having a iinger engaging portion at one end thereof, a transverse recess in the end of said iinger engaging portion providing transversely disposed spacedarms, aligned bores in said arms, a lead slidably andv rotatably received in said aligned bores and a resilient rotating vmember received on said lead and frictionally gripping the same between said arms whereby upon movement of a pencil along a straight edge with said member engaging the same said lead will be rotated to provide aline of uniform width.

DAVID GRAY FALCONER.

No references cited. 

